Sarah C Crosby1, Morgan Ivens-Duran2, Mark D Bertness2, Earl Davey3, Linda A Deegan1, Heather M Leslie4. 1. Brown University, Ecology and Evolutionary Biology, Box G-W, Providence, Rhode Island 02912 USA Marine Biological Laboratory, Ecosystems Center, 7 MBL Street, Woods Hole, Massachusetts 02543 USA. 2. Brown University, Ecology and Evolutionary Biology, Box G-W, Providence, Rhode Island 02912 USA. 3. U.S. EPA, Office of Research and Development, National Heath and Environmental Effects Research Laboratory, Atlantic Ecology Division, Narragansett, Rhode Island 02882 USA. 4. Brown University, Ecology and Evolutionary Biology, Box G-W, Providence, Rhode Island 02912 USA Marine Biological Laboratory, Ecosystems Center, 7 MBL Street, Woods Hole, Massachusetts 02543 USA Brown University, Institute at Brown for Environment and Society, Box 1951, 85 Waterman Street, Providence, Rhode Island 02912 USA.
Abstract
PREMISE OF THE STUDY: Salt marshes are highly productive and valuable ecosystems, providing many services on which people depend. Spartina alterniflora Loisel (Poaceae) is a foundation species that builds and maintains salt marshes. Despite this species' importance, much of its basic reproductive biology is not well understood, including flowering phenology, seed production, and the effects of flowering on growth and biomass allocation. We sought to better understand these life history traits and use that knowledge to consider how this species may be affected by climate change. METHODS: We examined temporal and spatial patterns in flowering and seed production in S. alterniflora at a latitudinal scale (along the U.S. Atlantic coast), regional scale (within New England), and local scale (among subhabitats within marshes) and determined the impact of flowering on growth allocation using field and greenhouse studies. KEY RESULTS: Flowering stem density did not vary along a latitudinal gradient, while at the local scale plants in the less submerged panne subhabitats produced fewer flowers and seeds than those in more frequently submerged subhabitats. We also found that a shift in biomass allocation from above to belowground was temporally related to flowering phenology. CONCLUSIONS: We expect that environmental change will affect seed production and that the phenological relationship with flowering will result in limitations to belowground production and thus affect marsh elevation gain. Salt marshes provide an excellent model system for exploring the interactions between plant ecology and ecosystem functioning, enabling better predictions of climate change impacts.
PREMISE OF THE STUDY: Salt marshes are highly productive and valuable ecosystems, providing many services on which people depend. Spartina alterniflora Loisel (Poaceae) is a foundation species that builds and maintains salt marshes. Despite this species' importance, much of its basic reproductive biology is not well understood, including flowering phenology, seed production, and the effects of flowering on growth and biomass allocation. We sought to better understand these life history traits and use that knowledge to consider how this species may be affected by climate change. METHODS: We examined temporal and spatial patterns in flowering and seed production in S. alterniflora at a latitudinal scale (along the U.S. Atlantic coast), regional scale (within New England), and local scale (among subhabitats within marshes) and determined the impact of flowering on growth allocation using field and greenhouse studies. KEY RESULTS: Flowering stem density did not vary along a latitudinal gradient, while at the local scale plants in the less submerged panne subhabitats produced fewer flowers and seeds than those in more frequently submerged subhabitats. We also found that a shift in biomass allocation from above to belowground was temporally related to flowering phenology. CONCLUSIONS: We expect that environmental change will affect seed production and that the phenological relationship with flowering will result in limitations to belowground production and thus affect marsh elevation gain. Salt marshes provide an excellent model system for exploring the interactions between plant ecology and ecosystem functioning, enabling better predictions of climate change impacts.